Reuters and the New York Daily News reported late Monday that the stars were cleared for the trip by the U.S. government under a cultural license. But there has been no official confirmation of this from either the Carter family or the feds. (UPDATE, 4/10: Feds authorized trip as “educational”) On Monday night, Sen. Marco Rubio (R-Fla.) added his voice to the concerns earlier raised by two vigilantly anti-Castro members of Congress.

“The Obama Administration should explain exactly how trips like these comply with U.S. law and regulations governing travel to Cuba,” Rubio said in a statement to Florida newspapers, “and it should disclose how many more of these trips they have licensed.” Rubio added that cultural-exchange waivers “have been abused by tourists who have no interest in the Cuban people’s freedom.”

Fact is, it’s not even that hard for non-celebrities to travel to Cuba these days.

“I was there this New Year’s to visit cousins,” Septime Webre, artistic director of the Washington Ballet, told us Monday. He’s also been authorized to go on “cultural” exchanges, one of the eight approved purposes allowed by the Treasury Department, which enforces the 53-year-old travel embargo. The Obama administration has also loosened up “people-to-people” exchanges to promote democracy.

But pure tourism — though pretty easy if you fly through a third country — is still a no-no for Americans and subject to substantial fines. The pictures of Beyoncé and Jay-Z dining out and strolling through Old Havana chafed Cuban-Americans. So far, the Treasury Department hasn’t mustered a response to Reps. Ileana Ros-Lehtinen and Mario Diaz-Balart on whether it authorized the trip. “The Office of Foreign Assets Control has received the letter and is working on a response right now,” a Treasury spokesman told us.